Carbonaceous particles emitted from cooking activities in Portugal

PM_2.5 samples were collected from the exhaust stacks on the roofs of a university canteen, a charcoal-grilled chicken restaurant and a wood-oven roasted piglet restaurant. The use of thick exhaust hood filters and also gas and electricity as energy sources for cooking in the kitchen of the university canteen contributed to the emission of much lower PM_2.5 levels (24-127 µg m^-3) compared to the restaurants. The charcoal-grilled chicken restaurant emitted particles at concentrations from 26 to 127 mg m^-3. In the exhaust of the wood-oven roasted piglet restaurant, PM_2.5 ranged from 192 mg m^-3, when vine cuttings were used to fire up the ovens, to 203 µg m^-3, at the final stage of roasting. Organic carbon (OC) represented, on average, 49% of the PM_2.5 mass in samples from the canteen, while elemental carbon (EC) accounted for 1-6%. The OC and EC contents in aerosols from the charcoal-grilled chicken restaurant ranged from 73 to almost 95% and from 0.4 to 1%, respectively. Very high organic contents in the smoke exhausted from the piglet restaurant were also determined. However, the EC mass percentages in PM_2.5 from this restaurant are higher than those found in samples from the other establishments.